This application claims the benefit of and priority from Japanese Applications No. 2001-359110 filed Nov. 26, 2001 and No. 2002-212785 filed Jul. 22, 2002, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a cap device for detachable attachment to a opening member of a fuel tank.
2. Description of the Related Art
One example of a conventional tank cap devices is disclosed in U.S. Pat. No. 4,830,058. The fuel cap comprises an outer shell having a gasket attached for providing closure to the opening of a filler neck; a cover having a handle and mounted on the outer shell; and an interconnecting mechanism between the outer shell and cover for switching between a transmission mode, in which rotational torque of the cover is transmitted, and a non-transmission mode in which same is not transmitted. The interconnecting mechanism is provided with an actuating button exposed at the top face of the handle; by pressing the actuating button one may switch between transmission mode and non-transmission mode to open/close the opening with the fuel cap. With the gas cap closed, the cover and handle freely rotate with respect to the outer shell so that if subjected to an external force the cover and handle will simply spin without turning the outer shell, thereby preventing loss of seal by the gasket.
However, the cap has the drawback that when attaching or detaching the fuel gap, it is difficult to discern how it should be operated, i.e., that pressing the actuating button allows the cap to be attached or detached, and is thus not easy to use. Because the actuating button is located on the handle, the handle needs to be larger, which has the drawback of requiring a larger space to accommodate it around the opening of the tank.
An object of the present invention is to provide a cap device that maintains a tight seal when subjected to external force, while at the same time providing ease of operation and taking up minimal space.
In accordance with one embodiment of the present invention, a cap device comprising a cap configured to open and close a tank opening. The cap comprises a closer for closing the tank opening with air-tight sealing at a closing position; a handle mechanism having a handle, the handle being switchable between a handling position and a retracted position, the handling position being a position for opening and closing the closer, the retracted position being a position in which the tank opening is closed, and the handle in the handling position being configured to project outwardly from an upper portion of the closer a greater distance than in the retracted position; andan interconnecting mechanism provided between the handle mechanism and the closer, for transmitting to the closer rotational torque in a closing direction and opening direction when the rotational torque is applied to the handle mechanism. The interconnecting mechanism comprises a clutch mechanism having a clutch member, the clutch member setting transmission mode wherein the rotational torque in the closing direction and the opening direction is transmitted from the handle to the closer when the handle is placed in the handling position; and the clutch member setting non-transmission mode wherein the rotational torque in the opening direction is not transmitted from the handle to the closer and the handle mechanism rotates freely in the opening direction when the handle is placed in the retracted position.
The cap device pertaining to the invention is designed such that when the handle of a handle mechanism is turned, rotational torque of the handle is transmitted to a casing main body via a clutch mechanism and torque transmission mechanism of an interconnecting mechanism, so that the tank opening is provided closure by means of the casing main body in such a way that rotational torque in the closing direction does not exceed a predetermined level. With the handle in the handling position, the casing main body disengages from the opening through application of rotational torque in the opening direction. By placing the handle in the handling position, rotational torque is readily transmitted to the handle, providing ease of attachment and detachment.
With the handle in the retracted position, on the other hand, the clutch mechanism is disabled from transmitting rotational torque in the opening direction, and if rotational torque should be applied to the handle in this state it will simply turn freely with respect to the casing main body. Thus if the handle should be subjected to external force the opening direction during a collision or the like, it will simply turn freely so that no rotational torque is transmitted to the casing main body via the interconnecting mechanism, thus avoiding loss of seal.
With the cap closed, the handle turns freely in the opening direction allowing the user to turn the handle to a desired position, thereby improving the ease of attachment and detachment.
In a preferred embodiment the clutch mechanism comprises a first clutch unit for transmitting rotational torque in the closing direction in both the handling position and retracted position; and a second clutch unit for transmitting rotational torque in the opening direction when the handle is in the handling position.
Since the first clutch unit transmits rotational torque regardless of the position of the handle, i.e. even with the handle not in the handling position, the tank opening can be closed by the casing main body even if the user has neglected to move the handle to the handling position. With the handle in the retracted position, the first clutch unit and second clutch unit turn freely in the opening direction, preventing the casing main body from turning under external force and resultant loss of seal.
In a preferred embodiment the handle mechanism comprises a cover covering the interconnecting mechanism; and an axial support mechanism for axially supporting the handle so as to allow operation thereof between the handling position and retracted position relative to the cover. Where the axial support mechanism comprises an urging mechanism for urging the handle towards the retracted position, the need for the user to return the handle to the retracted position is obviated, providing exceptional ease of use and preventing the handle from chattering or emitting noise when subjected to vibration.
In a preferred embodiment the urging mechanism comprises a cam having a cam face; and a resilient cam support piece for producing urging force towards the retracted position by means of following the cam face as the handle is rotated. This arrangement obviates the need for a separate coil spring or the like, so that fewer parts are required.
In a preferred embodiment the clutch mechanism comprises a clutch urging mechanism comprising a cam face formed on the handle and a clutch spring that urges against the clutch member. The clutch urging mechanism is designed such that by moving the handle from the retracted position to the handling position the clutch member is pushed via the cam face and switched to transmission mode; and by moving the handle from the handling position to the retracted position the clutch member is switched to non-transmission mode under the urging by the clutch spring. With this arrangement, the arrangement for switching the handle can be optimized.
The clutch spring may be provided as a resin spring integrally formed with the clutch member or torque member, thereby obviating the need for a separate coil spring or the like, so that fewer parts are required.
The urging mechanism may be designed so that urging force of the handle moving from the handling position to the retracted position reaches a greater level at an angle in proximity to the retracted position; and the clutch spring may be designed so that urging force of the handle moving from the handling position to the retracted position reaches its a greater level at an angle in proximity to the handling position. With this arrangement, the angle of moving the handle is distributed to two resin springs so that resin springs are not subjected large deformation, thereby avoiding damage or change in spring force due to deterioration over a period of years. Where the cap device is deployed in a vehicle subjected to vibration, the handle, being urged by means of the urging mechanism, does not produce noise due to vibration.
The clutch spring may be placed so as urge the torque member while positioned with respect to the casing main body. With this arrangement the torque member is supported while being urged against the casing main body, thereby preventing vibration noise due to vibration transmitted to the tank, as well as providing stable transmission of rotational torque.
The clutch spring may comprise an arm formed as a cantilever piece arranged coplanar with the torque member or clutch member and supported at one thereof; and a pushing protrusion that extends from the distal end of the arm, so that urging force is created through pushing by the pushing protrusion. With this arrangement, urging force can be adjusted in a simple manner simply by setting the pushing protrusion to the proper height.
In yet another preferred embodiment herein, the casing main body comprises a casing body for sealing the tank opening and having a casing interlocking portion for interlocking with a opening interlocking portion by means of turning by a predetermined angle.
According to the cap device pertaining to the invention, when the actuating portion of actuating means is rotated rotational torque of the actuating portion is transmitted to the casing main body via the interconnecting mechanism, causing the casing main body to mate with the tank opening member into the closed position in order to close the tank opening.
With the actuating portion in the handling position, the resultant interconnected state enables rotational torque to be transmitted, whereby application of rotational torque in this state causes the casing main body to close the tank opening. Once the casing main body closes the tank opening the actuating portion assumes the retracted position. In storage transmission rotational torque is not transmitted so that the actuating portion turns freely with respect to the casing main body. Accordingly if the actuating portion should be subjected to external force e.g. in a collision, it will turn freely without transmitting rotational torque to the casing main body via the interconnecting mechanism, preventing loss of seal.
With the cap closed, the actuating portion turns freely, allowing the user to turn the actuating portion to a desired position, thereby improving the ease of attachment and detachment.
In a preferred embodiment the actuating portion will consist of a handle supported on the casing main body so as to be rotatable about a support axis, and switched between a handling position and a retracted position by being upraised or lowered.
In yet another preferred embodiment of the invention the casing main body comprises a casing body for sealing the tank opening and having a casing interlocking portion for interlocking with the opening interlocking portion through rotation by a predetermined angle; and a cover rotatably mounted on the casing body and having the handle rotatably supported thereon.
In a preferred embodiment the interconnecting mechanism comprises a torque plate rotating in unison with a cover and having a torque piece interlocking portion; and a casing interlocking portion formed on the casing body and having a body interlocking portion switchable between interconnected mode and non-interconnected mode by interlocking or non-interlocking with the torque piece interlocking portion, the torque piece interlocking portion and body interlocking portion are designed to disengage at rotational torque above a predetermined level through rotation in the closing direction, and to rotate in unison with the casing body through rotation in the opening direction, and the handle comprises a cam that in association with movement between handling position and retracted position moves the torque plate to switch it between interconnected mode and non-interconnected mode.
The actuating means may comprise a spring for urging the handle so as to move it to the retracted position when released from the handling position. This enables the handle to move reliable to the retracted position. In a preferred embodiment the spring is formed as a cantilever piece extending integrally from the torque plate, with one end of the cantilever piece urging the casing body by pushing against it, or formed as a cantilever piece extending integrally from upper portion of the casing body, with one end of the cantilever piece urging the torque plate by pushing against it. By integrally forming the spring with the torque plate or casing, the number of parts can be reduced.